Conical sounding post or pillar for musical instruments of the violin class



July 16, 1940. H PROEBSTEL 2,208,081

CONICAL SOUNDING POST OR PILLAR FOR MUSICAL INSTRUMENTS OF THE VIOLIN CLASS Original Filed Nov. 23, 1937 Patented July 16, 1940 UNITED STATES CONICAL SOUNDING POST OR PILLAR FOR MUSICAL INSTRUMENTS OF THE VIOLIN CLASS Herbert F. Proebstel, Los Angeles, Calif.

Application November 23, 1937, Serial No. 176,025 Renewed December 13, 1939 2 Claims.

This invention is a sound post of pillar for musical instruments of the violin class.

The invention has for an object the provision of a hollow, sounding post of such a structure, 5 material and method of construction as will materially improve or deepen the tone performance such instruments as violins, Violas, cellos and others of the class.

An object is to provide a sounding post of this improved type which may be readily installed in a given violin-type instrument after its completion, or embodied in the original construction process.

Another purpose is to provide a sounding post of hollow, thin-Walled structure including a large upper end to abut the usual spruce board top and of a form converging therefrom to a smaller or foot end abutting the usual hard wood bottom of the instrument and in this connection a pro- 20 vision is included for the flow of air to and from the chamber of the post or pillar to avoid a dead-air pocket or damping effect on the vibrations set up in the material of the-pillar and in the air cell or chamber in the pillar.

25 Also an object is to provide a sounding pillar of a material such as wood of suitable wall thickness and rigidity to provide for the desired mutual transfer of sound vibrations from the top board to the bottom board of the instrument,

30 and especially to provide for production of a hollow wood, or fibrous or composition pillar with a thin wall which is made or produced by a process which will enable the use of a light and medium hard material rendered stiif, firm or rigid by the 35 application thereto of a liquid which will absorb into the material to armor or reinforce it.

The invention consists in certain advancements in this art as set forth in the ensuing disclosure and having, with the above, additional objects 40 and advantages as hereinafter developed, and whose construction, combination and details of means, and manner of production will be made manifest in the description of the annexed illustrative embodiment; it being understood that 45 modifications, variations and adaptations may be resorted to within the scope, principle and spirit of the invention as it is more directly claimed hereinbelow.

Figure 1 is a broken-away, side elevation of a 50 violin showing the installed pillar or post.

Figure 2 is a sectional elevation of the improved pillar.

The conventional violin 2 includes a top board 3 usually of spruce or other mediumly soft wood,

55 and a bottom 4 of a considerably harder wood.

and these are braced, under the bridge 5, usually by a solid, wooden pillar or post.

While it has been proposed for a long period to employ a hollow pillar it has not been sufficiently practical to have become fairly known, or even 5 more than rarely used.

However, after years of constructional experience in the production, repair and alteration of various violin type instruments, and the performance of music on the same I have successfully produced an integral, thin-walled post or sounding pillar of unique form and outstanding tonal deepening performance when rigidly set in the violin chamber.

The sounding pillar here disclosed consists of an integral, elongated tube 6 preferably of soft wood or a suitable equivalent, the larger and upper end of which, for a given size instrument, say

a violin of standard size, is of about three-eighths of an inch diameter whilst the smaller, lower or bottom end has a diameter of about one-half that dimension. It will be seen that the large end of the pillar is set against the soft, top board 3 and the smaller bottom end is set on the hard, bottom board 4.

The effect of such a peculiar arrangement is that the force of the waves of vibration collected from the top board adjacent to the foot of the string carrying bridge 5 is condensed in a converging column and impacted onto the bottom board in an area which is but one quarter that of the upper, larger end of the pillar.

The wall of the pillar is substantially of uniform thickness and the length of the pillar is parallel to the grain of the wood, if the pillar is made of an integral piece of wood, or of a laminated block of wood. In order to insure rigidity or strength to the conical tube, if of wood, or other suitable porous or fibrous composition, the pillar is given an inner and outer coat of liquid incorporating a hardening agent; the coat comprising as an example a mixture of litharge and varnish, which when dry and hard will form an armor 8 impregnating and covering the wall of the pillar.

The pillar is itself preferably of a non-metallic material.

The upper, large end of the pillar 6 is shown as notched or castellated at 1 to air-vent the bore chamber of the post or pillar to facilitate free vibration of the thin wall by a breathing of the air from the bore, and thus avoiding a dead air space in the pillar.

What is claimed is:

1. A sound post for violin class instruments 555 consisting of a non-metallic post of conical form conical features having a common axis and the externally from end to end and provided with a smaller end of the post being applicable to the conical bore converging in the same direction as bottom board. the outer surface, whereby to form upper and. 2. The sound post of claim 1, and the wall of 5 lower annular surfaces of difierent area to abut the post being of substantially uniform thickness. 5

the top and bottom boards of the instrument; the HERBERT F. PROEBSTEL. 

